Analysis of the advantages and disadvantages of permanent magnet motors

In recent years, the use of permanent magnet motors is more and more people, why do people flock to choose permanent magnet motors? Because the permanent magnet motor has a lot of advantages, so people choose it. Specifically what are the advantages, the next to give you a brief discussion of the advantages of permanent magnet motors are what it!

1. Middle and low-speed power generation performance is good

Power level is the same, idle speed, permanent magnet generator than the excitation type generator output power is twice as high, that is to say, permanent magnet generator of the actual power level of excitation type generator.

2. Simple structure, high reliability

Permanent magnet generator eliminates the excitation winding, carbon brush, slip ring structure of the excitation generator, the whole structure is simple, avoiding the excitation winding of the excitation generator is easy to burn, broken wire, carbon brush, slip ring is easy to wear out and other faults, reliability is greatly improved.

3. It can significantly extend the battery life and reduce the battery maintenance work.

The main reason is that the permanent magnet generator adopts the switching rectifier voltage stabilization, high precision voltage stabilization and good charging effect. It avoids the shortening of battery life caused by over-current charging. The open rectifier output of permanent magnet generator adopts small current pulse charging for the battery, and the charging effect is better with the same charging current, thus prolonging the service life of the battery.

4. Small size, light weight, high specific power

The adoption of permanent magnet rotor structure makes the internal structure design of generator arranged in a compact way, and the volume and weight are greatly reduced. The simplification of the permanent magnet rotor structure also reduces the rotor inertia, increases the practical speed, and the specific power (i.e., the ratio of power and volume) reaches a very high value.

5. Adoption of self-starting voltage regulator

There is no need for an external excitation power supply. The generator can generate electricity as soon as it rotates. When the battery is damaged, as long as the engine is running, the car charging system can still work. If there is no battery in the car, as long as you turn the handlebar or slip the car, you can also realize the ignition operation.

6. High efficiency

Permanent magnet generator is an energy-saving product. Permanent magnet rotor structure eliminates the excitation power required to generate the rotor magnetic field and the mechanical loss of carbon brushes and friction between the slip rings, making the permanent magnet generator efficiency greatly improved. 

Ordinary excitation type generator in the speed range between 1500 rpm to 6000 rpm average efficiency is only 45% to 55%, while permanent magnet generator can be as high as 75% to 80%.

7. No radio interference

Permanent magnet generator without carbon brushes, no slip ring structure, eliminating the carbon brushes and slip ring friction generated by radio interference; elimination of electric sparks, especially suitable for explosive hazardous environments, but also reduces the generator on the ambient temperature requirements.

8. Especially suitable for working in the humid or dusty environment.

It is because the permanent magnet motor has the advantages of the above eight points, so we will choose the permanent magnet motor to use. Of course, everything is not perfect, the above is the introduction of the advantages of permanent magnet motors, anything has its own advantages and disadvantages, permanent magnet motors are no exception, it is not only so many advantages, but also has a small part of its shortcomings.

If the permanent magnet motor is not used properly, when working at too high or too low a temperature, under the action of the armature reaction produced by the inrush current, or under severe mechanical vibration. It is possible to produce irreversible demagnetization, so that the performance of the motor degradation, or even can not be used. Therefore, special attention should be paid to the use of permanent magnet motors.